Dropbox, the file-hosting service that allows users to share and access documents, photos and videos from anywhere, is the 800-pound gorilla among private companies backed by venture capital money. Earlier this year, the company raised another $250 million in a funding round, bringing its total to $1.1 billion since it was started in 2007 with seed money from Y Combinator. Today top investors include BlackRock, Accel Partners and T. Rowe Price.

Dropbox, founded by two software engineers that studied at MIT—Drew Houston and Arash Ferdowsi—is now reportedly valued at around $10 billion. About 4 million businesses use Dropbox.

To compete with rivals such as Box.com, the company is now selling security software and other premium features to companies whose employees use the service. Houston isn't ruling out an eventual IPO but has said that, for now, he likes being able to just focus on attracting the best talent and building the best products.

How did you come up with your big idea?

"We started our journey seven years ago by creating a 'magic folder' as a place to keep your stuff safe, and it remains at the center of our service."-Drew Houston, co-founder and CEO

CNBC's Disruptor 50: Data storage

CNBC's Julia Boorstin looks at which data storage providers are disrupting the industry, as well as which corporate giants are being disrupted.